The role of lymphatics in the development of hemodynamic pulmonary edema and in the clearance of interstitial fluid during the resolution of acute pulmonary edema will be studied in dogs subjected to rapid, intravenous fluid infusion. We showed that lung lymphatics respond slowly to rapid increases in the net fluid filtration rate. We will test the hypothesis that accumulation of interstitial edema fluid is the result of the mechanism to increase the rate of fluid removal by lymphatics. We also demonstrated that acute lymphatics are not an important route of removal of lung edema fluid. We will determine the rate of clearance of interstitial fluid.